1. Field of the Invention
The present invention relates to an analog-to-digital converter (ADC), and more particularly, to an ADC of a parallel type which converts analog signals to digital signals using Microelectromechanical Systems (MEMS) technology.
2. Description of the Related Art
Diverse signals in nature change to analog continuously over time. In order to understand such a phenomenon in nature, the size of the analog signals need to be measured over time. The values are processed and analyzed using a computer, but in order for the computer to process and analyze analog signals, a device for converting the analog signals into digital values which are able to be processed in the computer is required. Such a device is an analog-to-digital converter (ADC).
An ADC may be fabricated by Microelectromechanical Systems (MEMS) technology. MEMS technology may also be referred to as micro systems, micromachines, or micro mechatronics, and means developing mechanical devices with microscopic precision machinery technology. That is, an ADC may be miniaturized using MEMS technology.
Various types of ADC are available, including a parallel ADC, a single slope ADC, a dual slope integrating ADC, and a successive approximation ADC. The parallel ADC uses an operational amplifier (Op-Amp) as a comparator, and encodes a signal to be output into a binary shape to output the signal in a digital form. If input voltage is higher than reference voltage, the comparator outputs voltage corresponding to logical value 1.
The parallel ADC may comprise a plurality of resistors to set reference voltage, a plurality of comparators to compare voltages with reference voltage, and an encoder to output digital signals.
If an ADC comprises a plurality of resistors and comparators, the resistors and comparators would consume a great amount of power. But since more resistors and comparators are required to implement high resolution and high speed, far more power is consumed. Specifically, to implement an N-bit ADC, 2N resistors and 2N-1 comparators are required. As the ADC of the higher bits is implemented, the power consumption increases exponentially.
As an ADC consuming less power is preferred, what is needed is an ADC for achieving high resolution and high speed with lower power consumption.